1. Field of the Invention
This invention relates to folding chairs and stools, specifically to an improved design for a folding stool which in its folded state makes a small and compact package and which when opened permits the user to sit at normal chair height.
2. Description of Prior Art
From ancient times man has found it useful to have a simplified backless chair or stool to sit upon, especially for brief periods, and long ago he discovered the advantage of portability of such a piece of furniture. A stool which could be folded into a compact size and shape, while also sufficiently strong and serviceable, became the object of numerous inventors.
Many different variations of the folding stool have been developed over the years, but relatively few have survived in the marketplace. The principal reasons for lack of commercial acceptability include: complexity or relative impracticality of design, expense of manufacture, and lack of aesthetic appeal. Those types which have remained acceptable in the marketplace are used for such diverse activities as camping, fishing, hunting, hiking, by artists painting in the field, by spectators at sporting events and games such as baseball, football, soccer, in watching horse racing, auto racing and the like, in watching golf tournaments, parades, for walks in the woods and for strolls by the elderly. In such and similar uses a compact folded size and shape, reasonably light weight, and reasonably attractive appearance are important considerations, along with, of course, comfortable sitting.
Probably the simplest form of the folding stool and the oldest is the familiar camp stool whose frame and support members sometimes of wood and now more commonly of tubular steel or aluminum, form an inverted U-shape. Two such U-shaped parts are pivotally connected by means of pins or rivets disposed at approximately the middle of their vertical sides, allowing the two parts to open into an X-shape, with an attached flexible seat, usually of canvas or duck, stretching across the top of the X and preventing further opening of the stool. When folded, the two U-shaped parts close one against the other, with the flexible seat folded or tucked in between the folded frame parts.
Functionally this design derives from the X-shaped supports used in chair design for centuries in many different countries and cultures, including Chinese, Egyptian and Roman. It was but a short step in concept to making the support members collapsible or foldable. Hence, this design and its contemporary adaptations in folding stools are of ancient heritage. Its continued success rests on factors of simplicity, practicality and low cost.
Yet, there are objections to this familiar design. Aesthetically such a stool cannot be said to be attractive to carry about, for example at golf tournaments, although it is practical to use and inexpensive to make. Aesthetic considerations aside, a more serious objection is the size and shape into which this stool can be folded for carrying and storing. If the stool were made so that the user could sit at normal chair height (17" or 18"), the vertical leg members would have to be 22" or 23" in length. Typical width of the seat frame is 10". Dimensions of the folded stool would then approximate 10".times.22" or 10".times.23", with the thickness of the package determined by the thickness of the legs in their folded state. This is not a desirable size or and attractive package for carrying about.
When the maximum folded dimension of the aforementioned design is made smaller than 10".times.22", the seat height becomes lower. When the folded package is made of a size considered reasonably desirable for carrying about, the seat height is lowered to a point where the stool becomes significantly less convenient to use. Those less physically fit, and older users in particular, find some difficulty in lowering themselves to the required level for sitting, or they may simply perfer not to.
Another device sometimes used in spectator activity is the "shooting stick", used in England and Europe beginning in the nineteenth century and later in the U.S. This portable seat is convenient in that it can readily be carried like a cane. The device is essentially a metal tube or post with a folding seat on one end a spike with flange on the other end. It has contemporary variations with the tube made of aluminum and an aluminum seat frame, the folding seat of leather or fabric, or with a "flip-top" hinged seat of rigid plastic, with a handle formed by or cut out of the seat. The main objections to this type of portable seat are: (a) the seat is quite small and not comfortable to use for any length of time and (b) the single leg or post obliges the user while seated to brace himself or herself with his or her own two legs spread out in a particular way, thus forming the second and third legs of a tripod, so to speak. Bracing oneself thus can become tiresome.
Another type of stool, probably thought to be an improvement over the "shooting stick", has a principal leg or post in the shape of a cane, with a crook at the top to serve as a handle, and with a hinged seat and two additional legs pivotally connected to the principal leg so as to fold against it. The result is a cane with cumbersome and ungainly attachments.
The folding stool invented by Neff and patented in 1917 (U.S. Pat. No. 1,215,689, which itself is an improvement over U.S. Pat. No. 1,134,057 issued in 1915, also to Neff) is intended to be folded and carried in a coat pocket. In the size as marketed, the user is obliged to lower himself to a seat height of about 14", a necessity objectionable to many users. The frame of this stool is made of heavy galvanized steel wire and hence the stool is not aesthetically attractive. If the stool were made in larger dimensions so that the user could sit at a more comfortable height, the stool would become more ungainly in size and appearance. An additional important objection is the necessity to use links and connectors which must be set or attached both horizontally and vertically in order to provide necessary bracing.
Several other patents appear to be relevant to my invention:
Travis, U.S. Pat. No. 181,225 (1876) discloses a folding chair which is a combination of folding seat with supporting frame comprised of hinged and pivoting parts. However, Travis does not show a set of support members which are connected by a double acting hinge which permits pivoting of the support members about a pair of axles over the 180.degree. horizontal, as will be shown in my invention. The Travis chair, moreover, cannot provide seating at a comfortable and normal chair height while also allowing the folding of the chair into a compact size and shape.
The Mason U.S. Pat. No. 476,805 (1982) and Mix U.S. Pat. No. 1,157,795 (1915) both show a folding stool having a central post to which are pivotally connected supporting bars or legs by means of a fixed and slidable pair of sleeves or rings. Both employ systems to lock the sleeves in position on the central post when the stool is open for use.
Stoll, U.S. Pat. No. 1,390,836 (1921) is similar to Mason and Mix in that a post is used as a central support. Two pivot assemblies are positioned by a wing nut disposed on the bottom portion of the central post, which is threaded. The wing nut is rotated up the post, the lower pivot is brought into proximity with the upper pivot, thereby stretching the seat cover.
Bowman U.S. Pat. No. 615,135--1898) describes a folding stool having four pairs of bars connecting to a central pivot. There is an interlocking ratchet with pin that locks the stool in an open position, thereby preventing the stool from collapsing under the weight of the user.
The Neff, Bowman, Mason, Mix and Stoll stools are all made of a size that when folded are small enough to be carried in a coat pocket. Accordingly, they all have the objection of the previously mentioned low seat height. They would all likewise be of ungainly proportions if made to provide a comfortable seat height. Moreover, if any of them had sufficient appeal in terms of design, features and performance, one or more of them would likely be on the market today.